ONLINE HEMODIALYSIS TRAINING SESSION 1

The Renal System - A highly sophisticated filtration system - These systems help the body take in and use nutrients Iron, the food we eat - They also take out or remove waste products/substances the body cannot use The blood that runs through arteries and veins is one of the body s distribution systems. - It collects proteins, nutrients and chemicals from the digestive systems and distributes them to every cell and muscle in the body. - This provides them with the energy they need to function. - As cells function, as muscles are used, they produce waste products. - These waste products are collected by the blood This means the blood is not only a delivery system but a pick-up one as well. However, the blood cannot hold onto waste. It must get rid of it to make room for nutrient delivery and more waste pick-up. Page 1

Renal Anatomy Brief review of anatomy structures composing the renal system: (handouts showing positioning of structures and kidney internal structures) Structures of the urinary tract: kidneys, renal pelvis, ureter, bladder, and urethra Page 2

The Kidney - most people have two kidneys - lies about waist level more towards the back, ex. below the ribs - each weighs six ounces approximately the size of a fist Page 3

The Nephron - structural and functional unit of the kidney (urine is made inside the nephrons) - more than a million in each kidney - composed of glomerulus (filters) and tubules (reabsorbs) Page 4

Renal Physiology Primary functions of the kidney REMOVE - REGULATE - PRODUCE A. Remove waste (ex. toxins, poisons) and water B. Regulate chemical balance Otomeostasis and ph of blood/bodily fluids (electrolytes arid acid-base) C. Produce hormones to a. Regulate UP (blood pressure) b. Make RECs (red blood cells) c. Strengthen bones Page 5

HORMONES KIDNEY FUNCTION MEDICATION Renin Regulate BP Variety of BP Medications Erythropoietin Calcitriol Controls RBC Production Strengthen Bones Epogen (stimulates RBC production hematocrit) Zemplar or Hectarol (helps with conversion of vitamin D) Homeostasis steady state in the internal environment of the body Page 6

NOTE: 1. Red blood cells are made within the bone marrow. 2. The hormone produced in the kidneys that stimulates the production of red blood cells is called erythropoeitn. 3. Activated vitamin D helps calcium be absorbed in the intestines (from the intestines into the blood). 4. Without the presence of activated vitamin D, bone disease may result. 5. If the healthy kidney senses that the blood pressure is low, it gives off an enzyme called Renin. 6. EPO (Epogen) is given to increase a patient s red biood cell production (hematrocit). 7. Zemplar is a medication that contains activated vitamin D. Zemplar (activated vitamin D) is commonly given IV during treatment. Two other similar meds are Calcijex and Hectarol. Page 7

What Happens When The Kidneys Do Not Work Properly? When the kidneys start to fail, we end up with problems like uremia and anemia. Page 8

Uremia A high concentration of toxic substances in our blood. When the kidneys fail, these toxins build up in the blood causing problems in just about every part of our body. The kidneys no longer function properly and are unable to make urine. They have no way of eliminating the waste. If uremic symptoms appear when a patient is on dialysis, it means that more dialysis is needed. 2 Types of Toxins 1. Urea is the waste product of protein metabolism 2. Creatinine is the waste product of muscle activity Patients with uremia typically have flu like symptoms, including muscle aches and nausea. Page 9

Signs and Symptoms of Uremia Edema Hypertension Weight Loss/Anorexia Restlessness Itching Headaches Nausea and Vomiting Fatigue Weakness Dyspnea (shortness of breath) Complications of Uremia Pericarditis the inflammation of the membrane or sac that surrounds the heart this is a serious complication of uremia due to inadequate dialysis treatment for pericarditis is heparin(blood thinner) free dialysis Pruritis uremia can also alter skin integrity causing prunitis aka itching prunitis is caused by calcium phosphate crystals in the skin and decreased activity of the oil glands Page 10

Anemia A low number of red blood cells in our blood. Red blood cells carry oxygen all the cells in our heart. Oxygen is vital for normal cell functioning. Our kidneys help prevent anemia by producing a hormone which stimulates the production of RI3C. Anemic patients are always tired and feel a lack of energy. Patients are treated with a medication called Epogen. Signs and Symptoms of Anemia Page 11

Kidney Failure What happens in kidney failure? The kidneys can become damaged from disease or injury in which they no longer clean waste from the blood. Causes of kidney failure Diabetes the most common cause of kidney failure, hyperglycemia increases the speed of blood flow to the kidney, which puts a strain on the glomeruli and elevates the blood pressure. High blood pressure - 2nd most common cause of renal failure, high blood pressure can damage small arteries in the kidneys over a period of time. A vicious cycle begins and damage to the kidneys causes more serious high blood pressure. Cysts are fluid filled sacs. Having many cysts on the nephron can be harmful causing polycystic kidney disease. This is a genetic disease that can cause CKD Types of Kidney Failure Acute Kidney Failure Sudden reversible condition that causes decline of renal function Chronic Kidney Failure Gradual, slow onset of symptoms which becomes a permanent condition and is usually not reversible Page 12

Acute Kidney Failure (ARF) A sudden, reversible condition that causes decline of renal function. Acute kidney failure (or acute renal failure) is most often caused by illness, injury, or toxin that stresses the kidney. In some cases, patients who survive acute kidney failure recover their kidney function with the temporary support of dialysis. Chronic Kidney Failure (CKF) Permanent/non-reversible condition with slow/gradual onset of symptoms. Two most common causes of CKF are 1) diabetes (endocrine disease ) 2) hypertension (vascular disease) Page 13

Stages of Chronic Kidney Disease Stages of Chronic Kidney Disease Stage Description 1. Kidney damage with normal GFR >90 2. Kidney damage with mild GFR Moderate ~GFR 80-89 3. Moderate GFR 30-59 4. Severe GFR 15-29 Glomerular Filtration Rate (GFR) (mlimini t.73 m 2 ) 5. Kidney failure <15 or dialysis Page 14

Peritoneal Dialysis (PD) An alternative dialytic treatment for patients with ESRD. During the process of PD, the peritoneal cavity acts as the reservoir for the dialysate and the peritoneum as the semipermeable membrane across which excess body fluids and wastes are removed (ultrafiltration). The dialysate is infused into the peritoneal cavity via catheter, allowed to dwell for a fix time and then drained (effluent). This is called the exchange. Peritoneal dialysis can be done by patients in the comfort of their own homes, after they have received training. Page 15

Hemodialysis Is the most common treatment for End Stage Renal Disease. It involves the use of a machine with a pump that continuously circulates blood from a patient through an artificial kidney called a dialyzer then back to tile patient at no more than 500cc per minute. The Dialyzer 1. cleanses the blood by removing fluid and waste products 2. restores the concentration of other chemicals (electrolytes) to normal or neat normal levels Hemodialysis is usually required two or three times a week with each dialysis treatment lasting 2 to 6 hours. Page 16

Dialyzer Is a selective filter for removing toxic or unwanted particles from the blood. The filtration process uses a semipermeable membrane between blood flowing on the inside and dialysis fluid, called dialysate, flowing on the outside. Dialysate Is the mixture of treated water and carefully measured chemicals (acid and bicarbonate) that is used to clean the blood during dialysis. The following electrolyles (charged particles in our blood that are used in many cell functions) are found in unused or fresh dialysate: potassium, sodium, calcium, and chloride. Page 17

The Dialysis Process Osmosis The movement of fluid (water) across a semipermeable membrane from an area of lower concentration of particles to an area of higher concentration of particles. For example, picture a tea bag just being place in a tea cup. The tea cup full of water is the area of lower concentration of particles and the tea bag is the area of higher concentration of particles. As the tea bag is placed in the cup, the water from the cup will be drawn into the tea bag. Page 18

Diffusion The movement of particles from an area of high concentration to an area of low concentration through a semipermeable membrane. (hemodialysis works similar to this process) For example, picture the particles in a teabag filtering through the bag into the surrounding water. In hemodialysis it is the movement of particles (toxins, waste) from the blood (blood being a high concentration) into the dialysate (dialysate being a low concentration). Page 19

Filtration The trapping of particles inside the filter Ultrafiltration Is the result of additional pressure to squeeze extra fluid through the membrane. Example: it is like squeezing extra fluid out of the teabag by applying pressure on the teabag within the spoon. In hemodialysis, ultrafiltration is achieved by programming the machine to remove excess fluid. Sequential Ultrafiltration Removes water but not particles (wastes). This is also known as a puff. Here, no dialysate flow is needed the dialysis machine is placed in stand-by to start this process. The purpose of sequential ultrafiltration is to allow a larger quantity of fluid removal within a shorter time period. NOTE: In hemodialysis, wastes are removed by the process of diffusion In hemodialysis, fluid is removed by the process ultrafiltration Page 20

WEIGHT Dialysis patients have many hours in between treatments in which they have fluid weigh gain. This is because most patients on dialysis make little or no urine. A dialysis prescription calls for taking off enough fluid to bring a patient to an estimated dry weight (EDW) by the end of the treatment. Weight is removed by the process of Ultrafiltration in hemodialysis. Dry Weight and/or Estimated Dry Weight (EDW) Dry weight and/or estimated dry weight is the patient s ideal weight without extra fluid and with a normal blood pressure, the doctor prescribes a dry weight. We have to be able to calculate patient s weight gain in order to determine what is needed to be removed. Pre-dialysis weight = The patient s weight before treatment Estimated dry weight = The weight the doctor ordered for the patient (ideal weight) Last post-dialysis weight = The weight the patient left at after their last treatment Saline prime and rinseback = Saline given to patient before and after treatment What is the weight gain? Pre-dialysis weight - Last post-dialysis weight = Weight gain What is the fluid removal goal? Pre-dialysis weight Estimated dry weight = Fluid removal goal + Saline prime and rinseback Page 21

The artificial kidney or dialyzer is where the actual dialysis process takes place. Inside the dialyzer there are long hollow fibers that resemble straws. These hollow fibers are known as semipermeable. Semipermeable Membrane Is a thin layer of tissue or material that has small pores in it. The pores only let particles of certain size pass through. Coffee filters and tea bags are both semipermeable because they let the tiny flavor particles pass through but not the coffee grounds or tea leaves. NOTE: Red blood cells, white blood cells, protein and bacterial cannot pass through the membrane because these substances are larger than the membrane pores. Page 22

Within the dialyzer (artificial kidney) the dialysate is an the outside and the blood is on the inside - the two never meet. It s like oil and vinegar. NOTE: In the dialysis process the blood and dialysate flow countercurrent. Countercurrent flow is when the blood and dialysate flow in opposite directions. This allows for optimal cleaning of the blood. Page 23

How The Dialyzer Works The dialyzer is an artificial kidney made up of 10,000 hollow fibers with microscopic holes (semipermeable), where the patients blood passes through each fiber while dialysate (a salt solution that looks like water) bathes the outside of the fiber. Liquid can pass through the holes, as well as wastes and many electrolytes. The dialyzer works through diffusion, particles move from a higher to lower concentration) and filtration. Diffusion causes wastes and electrolytes to move from the blood into the dialysate during each dialysis treatment. Because of pressure differences, fluid is pushed from the blood into the dialysate, which is known as ultrafiltration. Thus, urine is made during dialysis, that is fluid, wastes, and electrolytes are removed from the blood enter the dialysate and then go down the drain. Since the dialyzer can only produce urine, the other functions of the kidney are assisted using medications. For example, Zemplar (activated vitamin D) is given intravenously (IV), as well as Epogen (erythropoietin). NOTE: One key difference between a healthy kidney and dialysis treatment involves time. While a healthy kidney functions 24 hours a day (168 hours a week), dialysis is only completed for approximately 4 hours, 3 times a week (only 12 hours a week). Dialysis patients therefore have many hours in a week when wastes, electrolytes, and fluid build between treatments. To help compensate, our patients restrict fluid and electrolyte intake. For example, phosphorus and potassium are two electrolytes that are often restricted. Page 24

NOTE: 1. Urine is made up of fluid, electrolytes and wastes. 2. Two examples of wastes in the urine are urea (from protein metabolism) and creatinine (from muscle activity). 3. The healthy kidney produces erythropoietin (EPO) which stimulates bone marrow to produce red blood cells. 4. The dialyzer is made up of approximately 10,000 hollow fibers. 5. During dialysis, diffusion causes wastes and electrolytes to move from the blood to the dialysate. 6. Pressure causes fluid to be pushed from the blood into the dialysate. 7. The most common form of activated vitamin D that our patients receive during dialysis is a drug called Zemplar. 8. Epogen is a drug given to increase patient s hematocrit. Page 25